Cross-Site Request Forgery (CSRF) in contao/core-bundle (CVE-2026-107848)
Summary
Vulnerability in contao/core-bundle (CVE-2026-107848). Risk of unauthorized operations or information disclosure. Exploitable via RequestTokenListener. Mitigation: upgrade to 5.7.12 or later.
Original description
The description as published by the source.
RequestTokenListener is the only generic REQUEST_TOKEN validator in Contao and it only runs on POST. On the GET side the guard is local and declarative, and it only fires when an act parameter is present. Every back end action dispatched through a different parameter therefore has no CSRF protection at all. This is a family rather than a single bug.
Impact
An attacker who gets a logged in back end user to load a URL performs back end actions as that user, with no token and no confirmation. Because the exposure follows from the dispatch mechanism rather than from one callback, every present and future key= action inherits it.
Honest bound. The victim must be authenticated in the back end and must load the URL, and the reachable actions are limited to the modules that user can access. We have not found a key= action that grants privileges; the ones we verified are destructive or state changing rather than escalating.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-107848 has been found in contao/core-bundle.
Attackers can target a specific entry point like RequestTokenListener over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 3.5/10.
What to do: upgrade contao/core-bundle to 5.7.12 or later.
If unsure, ask your IT team or search "contao/core-bundle CVE-2026-107848" on the vendor's site.
CVE-2026-107848 (contao/core-bundle) — CWE-352 / CVSS v3 3.5
Attack vector: remote (network-reachable)
Attack surface: RequestTokenListener / REQUEST_TOKEN / act
Patched: 5.7.12 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
CSRF (CWE-352) exists in contao/core-bundle. Attackers reach the vulnerable code path via RequestTokenListener.
Check the vendor advisory for the affected versions of contao/core-bundle. Attack surface: RequestTokenListener / REQUEST_TOKEN / act.
Severity: Low (CVSS 3.5/10). Risk of unauthorized operations or information disclosure.
Update to 5.7.12.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'contao/core-bundle' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'contao/core-bundle' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
contao/core-bundleを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade contao/core-bundle to 5.7.12ステージング環境で 5.7.12 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com